This invention relates to sheet metal panels that are provided with a thermal break. It also relates to doors made from a series of such panels joined by hinged couplings to serve in a garage door or the like. In particular the invention relates to a method of sealing such joints to minimize the passage of air there through.
Various technologies have been applied in the past to the joining of sheet metal panels to form doors having inner and outer faces. Further, such panels have been assembled with a series of hinged joints to provide a roll-up door. A particular application of this technology has been in the fabrication of garage doors.
It is useful to provide a thermal break between the pieces of sheet metal forming the inner and outer surfaces of a barrier such as a door. Particularly when the sheet metal is aluminum or steel, thermal conduction from an outer panel exposed to low temperatures can lead to the cooling of the inner panel with resulting condensation. Such condensation can eventually cause corrosion and damage to the door and its parts.
It is therefore one object of this invention to provide a means for joining two panels together that provides a thermal break for such panels.
It has been known to provide special shapes for adjoining edges of panels which are hinged to each other in order to minimize the risk that an object, e.g. a finger, may be pinched in the joint when the joint closes. Such edges are often provided with shapes of complementary curvature that permit the panels to be either aligned into a planar format, or oriented at an angle with respect to each other. Typically, one edge is generally of a convex, somewhat parabolic shape, while the other edge is concave with a complementary curvature. This minimizes the amount of gap that is formed when the joint opens.
The present invention incorporates into such a joint a sealing feature which minimizes the loss of air which might otherwise flow through the joint.
The invention in its general form will first be described, and then its implementation in terms of specific embodiments will be detailed with reference to the drawings following hereafter. These embodiments are intended to demonstrate the principle of the invention, and the manner of its implementation. The invention in its broadest and more specific forms will then be further described, and defined, in each of the individual claims which conclude this Specification.
In one broad aspect, the invention is a flexible joining strip preferably of resilient polymeric material providing two parallel slots to receive edges from respective inner and outer portions of a modular panel that is to form part of a roll-up door or wall. These panel portions are of a sheet material, preferably sheet metal. A central web separating the two slots provides the joining strip with a partially xe2x80x9cMxe2x80x9d-shaped cross-section. The central web extends below the base of the xe2x80x9cMxe2x80x9d to terminate in an inverted xe2x80x9cTxe2x80x9d-shaped flange with outwardly-extending lateral portions. The respective lateral portions of the xe2x80x9cTxe2x80x9d extend across the direct, aligned path of entry into the respective slots. The flange on the central web is, however, displaced sufficiently below the base of the xe2x80x9cMxe2x80x9d to provide an access path for entry of sheet edges into the respective slots.
The material of the joining strip has a thermal conductivity which is less than that of a metal. Thus, when serving to bind the seam between two metal sheets, the joining strip will provide a thermal break. The sealing strips may be fitted to the edges of the panel portions by sliding such strips onto the edges endwise. Alternatively, by forming the joining strip from material of a flexible nature, particularly when warmed, the outer sides of the slot may be flexed to admit the entry of the edges of the sheet material into the respective slots. Those edges may be bent or of a xe2x80x9chookedxe2x80x9d shape in cross-section to fit into the slots. The flange is positioned to block the direct removal of the preferably hooked edges from the slots. This provides a stable coupling between the two edges of the sheet material panel portions.
When a panel is to be formed by joining two separate metal panel portions together, the paired edges along the top and bottom of both of the inner and outer sheet metal panel portions may be joined along their longitudinal edges to provide an inner, enclosed volume. Alternately, a single sheet of metal can be bent to provide both the inner and the outer faces of the panel. In this latter case only a single pair of edges need be joined by the joining strip to provide a single seam. While this arrangement is an option, a disadvantage of this arrangement is that the sheet metal along one edge of the panel is continuous, without a thermal break being present. For maximum thermal isolation, panels should be formed with separate inner and outer sheet metal portions, joined by two, upper and lower seams. Further and preferably, such two piece panel portions are symmetrical when assembled, allowing such parts to be produced from a single production die. Also preferably, the interior volume of each panel is filled with a stiffening insulation material such as polyurethane foam.
As a preferred feature, the outer face of the flange portion of the web on the joining strip carries a sealing member in the form of a hollow, flexible tubular cylinder which can be compressed into a flattened position adjacent to the flange to provide a sealing member. Preferably this tubular cylinder is made of a resilient material. When panels are assembled into an articulated door or wall, at least one seam should be equipped to provide a sealing member along a joining strip. Preferably two seams from adjacent panel longitudinal sides or ends may be provided with sealing members that contact each other and provide an improved airtight seal for a door when closed. By use of compliant material for the sealing member, the sealing member may be compressed within the space between adjoining seams of two door panels when the panels are brought into planar adjustment. It is not, however, necessary, for both joining strips to carry sealing members. It is sufficient for one joining strip to provide the necessary seal.
To allow panels to be assembled into an articulated wall or door having pinch-resisting joints, one of the longitudinal boundary edges or faces of each panel is preferably shaped to be generally convex, while the other longitudinal edge face is generally concave. The precise shape of these ends is selected to provide a close but not obstructing fit between these respective faces when one panel is rotated about a hinged axis with respect to the other panel. In the course of this rotation a portion of the joining strip, or sealing member if present, positioned along the seam formed on either the concave or the convex end of one panel may brush against the inner surface of the end of the other panel. This contact provides a barrier to entry of objects into the joint. Contact as described is permissible, however, only to the extent that motion between the two parts is not obstructed.
In this manner a joint is provided which provides a minimal gap that may pinch a person""s fingers, acts as a thermal break between the inner and outer sheet metal portions of each panel, and further serves to create an airflow-resisting seal along the joints between panels when the panels are flattened out into a planar orientation with respect to each other.
The foregoing has provided a description of the invention and some of its optional aspects. The invention may be further understood by the description of the preferred embodiments, in conjunction with the drawings, which now follow.